Low oil warning turned on, so I added oil and after driving fifteen miles the oil warning light turned on again?

We can only handle one problem per question so you will need to start a new question for the fuel pump issue. It sounds like you have a valve cover that is leaking onto the exhaust manifold which causes the smell, and you have an oil level sensor that is no good. here is a generic guide on how to change out a valve cover gasket with instructions in the diagrams below to show you on your car. Also, I have included the location of the oil level sensor so you can check it out. I would drain the oil first.

https://www.2carpros.com/articles/replace-valve-cover-gasket

Check out the diagrams (below). Please let us know what happens.